Known magnetic closures include that shown in Mizuno, U.S. Pat. No. 3,129,477. Such a magnetic closure, without a safety feature may have a perceived lack of strength due to the absence of a mechanical closure.
In my previous patents, various mechanical clasps are shown in combination with a magnetic clasp. In particular, a further embodiment of the clasp described in U.S. Pat. No. 5,092,019, is described herein.